A roll film negative. On board the submarine Sealion (1959) towards the end of a long refit at Portsmouth. The photographer is in the forward torpedo compartment looking to port, aft and down at the aft bulkhead at 34 station from the centreline at 33 station. On the aft support beam of the torpedo reload racks is a notice headed 'Modification record equipment - P.L.C. Mk. I Mod. 10' and at the bottom of this beam is the Mk. 23 power load attachment. On the aft bulkhead are two torpedo battery alarm units above a televalve block holding rows of handwheels marked 'Return' and 'Pressure'. A vertical format negative.